This invention relates to a means for preventing moisture from coming in contact with electrical components in a container. More particularly, it relates to an improved telephone cable splice case, which is readily re-enterable.
In the telephone communication industry, signals are transmitted many miles over cable containing many pairs of conductors. Since this cable is sold in fixed lengths, usually several hundred feet each, it is necessary to splice cables together. The ends of corresponding conductors of abutting cables are tied or spliced together after their insulations have been trimmed, exposing their metallic conductors. In order to protect these exposed metallic conductor splices from the elements, such as moisture, the splices are housed in a splice case. If the cable is an air core type, which is normally used above ground on telephone poles, the splice case is usually under air pressure, and thus air acts as a filler in the splice case to keep out moisture. However, recently it has become a common practice to bury telephone cable underground. Moisture is a major problem in buried cable. To solve this problem, the industry uses a heavy grease filling in the core of buried cable. The splice case commonly used for buried cable is normally a jel compound which sets up after it has been injected into the splice case to form a hard rubber filler in an attempt to seal the case. One of the problems in using this type of rubber-filled splice case is that it is very difficult to re-enter the splice case to make repairs on the splices. The rubber itself must be cut through in order to get to the splices. Furthermore, once the rubber has been cut through, the fill material is often rendered useless, thus it must be re-filled or a new splice case must be used.
Furthermore, some moisture problems have occurred in this type of filled splice case in that the rubber material will not bond to grease coated polyethylene telephone conductor; thus, when the rubber sets up, it often leaves a gap between the individual telephone conductor and the rubber itself which leaves a channel for moisture to move through to attack the splice, and thus degrade the conductor.
Examples of filled splice cases are shown in U.S. Pat. Nos. 2,312,652 and 4,070,543.
Various electrical apparatus such as transformers have been housed on containers which are substantially filled with light oil. In the case of the transformer, the oil is used to keep the coils cool as well as provide insulation to prevent shorts. Normally, transformers are located on poles above ground. Electrical power lines normally enter the transformer box from the top and make connections to the windings of the transformer, which are immersed in oil. The oils which are used in the transformer box have a specific gravity of less than 1, as do almost all oils.
High voltage capacitors have used oils as a dielectric material. An example of an oil used in disclosed Dow Chemical Product Bulletin titled Dow Dielectric Fluid C-4, form No. 17.6-1347-78. The C-4 fluid is butylated monochlorodiphenyl oxide and has a specific gravity of 1.095.